Cleaning devices for chemical or electrochemical surface treatment plants

ABSTRACT

A cleaning device for chemical or electro-chemical surface treatment plants, comprising different treatment tanks into which the material to be treated is immersed, uses a movable spray booth which is transported to a preselected tank and stops in a position above said tank. The material having its treatment finished in said tank is lifted up through the bottom of said spray booth and is sprayed with cleaning liquid inside it.

United States Patent [191 Almegard et a1.

[54] CLEANING DEVICES FOR CHEMICAL OR ELECTRO-CHEMICAL SURFACE TREATMENT PLANTS Inventors: Svante G. Almegard, Savedalen; Harry A. H. Ericson, V. Frolunda, both of Sweden Assignee: Nordnero AB, Goteborg, Sweden Filed: Dec. 8, 1971 Appl. No.: 206,015

[30] Foreign Application Priority Data Dec. 10, 1970 Sweden ..16693/70 US. Cl. ..l34/76, 134/103, 134/135, 134/199 Int. Cl. ..B08b 3/02 Field 01 Search ..l34/76, 77, 94, 103, 134/135, 199

References Cited UNITED STATES PATENTS 5/1918 Sears ..l34/l99 UK 1 May 22, 1973 2,643,465 6/1953 Douglass ..134/103 X 2,849,745 9/1958 Madsen ..134/l35 X 3,106,927 10/1963 Madwed ..l34/76 FOREIGN PATENTS OR APPLICATIONS 454,596 1/1928 Germany ..134/135 11,364 12/1963 Japan ..l34/77 Primary Examiner-Robert L. Bleutge Att0meyDavid TOren et al.

[57] ABSTRACT A cleaning device for chemical or electro-chemical surface treatment plants, comprising different treatment tanks into which the material to be treated is immersed, uses a movable spray booth which is transported to a preselected tank and stops in a position above said tank. The material having its treatment finished in said tank is lifted up through the bottom of said spray booth and is sprayed with cleaning liquid inside it.

8 Claims, 3 Drawing Figures PATENTED MAY 2 2 I575 SHEET 2 OF 2 Fig. 2

Fig.3

CLEANING DEVICES FOR CHEMICAL R ELECTRO-CHEMICAL SURFACE TREATMENT PLANTS The present invention relates to a cleaning device for chemical or electro-chemical surface treatment plants.

The surface treatment operation in such plants is usually so performed that the material to be treated is immersed into a tank containing the solution to be deposited. As a rule such a surface treatment includes a number of subprocesses which in turn are divided up through a great number of cleaning operations. As an example we can mention that an electrolytic nickelplating process may comprise up to 25 different stations of treatment, most of them being water cleaning stations. The water consumption is thereby considerable and all this cleaning water will be polluted through metal salts, chromates, cyanides etc. There are involved great problems to have these poisons destroyed and the costs for this are closely direct proportional to the water quantities included.

By using a multistage cleaning according to the counter-current flow principle, so called cascade cleaning, the water consumption can be considerably reduced. The method requires however increased initial costs and space.

Another way to decrease the water consumption is to use so called mist-cleaning. This one which works in one stage can very closely be compared with a continuous stage cleaning. The mist-cleaning requires a high pressure to be effective. The technical equipment is complicated and stationary installations are extensive, as different cleaning stations after the various chemical processes are required.

It is an object of the present invention to provide a cleaning device in which fixed cleaning stations are eliminated, thereby decreasing the initial costs and production time.

Another object of the invention is to decrease the cleaning water consumption, thereby also decreasing the costs for water and its depoisoning. According to the invention part of this object is achieved in such a way that the water, which during the cleaning does not come into contact with the material under treatment, is recovered.

It has also been a requirement that the cleaning device shall be able to be used both for material suspended on a rack and for material in a barrel.

Other objects and advantages of the present invention will become apparent from a consideration of the following description taken in connection with the accompanying drawings, in which:

FIG. I shows as an example how the tanks can be arranged according to one embodiment of the invention, the tanks being disclosed from above;

FIG. 2 discloses the cleaning device according to the invention and shown from one end of the electroplating plant; and

FIG. 3 shows the cleaning device used for material in barrels instead of material suspended on racks.

In FIG. 1 la-le are tanks for the material to be treated, tank 1a for the degreasing, lb for the zincplating, for the copper-plating, 1d for the nickelplating and 1e for the chromium-plating. Usually there are series of cleaning liquid tanks after each such treatment tank.

According to the invention a cleaning liquid tank 2a-2e, as shown in FIG. 1, has been placed at the side of each treatment tank la-le. For cleaning of the liquid itself in said tanks 2 it can be inserted therein a filter as is shown at the tank 2d and is indicated as 3.

On a runway 4 (see FIG. 2) extending in the direction of location of the treatment tanks 1 there is running a spray booth 5 driven by a mechanism not shown. On the top of this booth there is a pulley block 6 which in turn controls the lifting and lowering of a rack 7 for the material to be treated, so that this can be brought down into and taken up from the treatment tanks la-le. For

this purpose the bottom of the spray booth 5 is provided with an opening 8. In the side walls of the spray booth 5 there are inserted nozzles 9 which through a pump 10 and a flexible tubing 11 are connected to the cleaning tanks 2. This is so arranged, that when the spray booth 5 is over the treatment tank la, so is the tubing 11 in the corresponding cleaning liquid tank 2a. When moving the spray booth S from one treatment tank to another the tubing 11 is moved from and to corresponding cleaning liquid tanks.

According to the present embodiment of the invention the tubing 11 has been lengthened by a part 12, so that they together form a U-sha.pe, the lower part of which will be in respective cleaning liquid tank. The part 12 of the tubing 11 is in its outer end connected to a clean-water supply 13. By means of for instance a solenoid valve 14 the nozzles 9 can be connected either to the cleaning liquid in the tanks 2 or to the cleanwater supply 13. Especially in the last stage it can be advantageous to spray the material with clean water.

Along the outer sides of the bottom of the spray booth 5 the bottom is provided with upwardly directed edges 15, from the lower part of which there goes a return tube 16. w

The material is suspended by the rack 7 in the spray booth 5 which is transported along the runway 4 to and above the first treatment tank la. Therein the material is immersed by means of the pulley block 6. After the treatment is finished there the material is lifted by means of the pulley block 6, so that the material is moved to a position opposite the nozzles 9. By means of the pump 10 the cleaning liquid is pumped from the tank 2a through the tubing 11 and is sprayed by the nozzles 9 onto the material supported by the rack 7. It is of no need to have an especially high liquid pressure. The liquid which hits the material is dropping down into the treatment tank 1a, while: the liquid which does not hit the material instead hits the walls of the spray booth 5 and runs down to the bottom edge 15 to be drained from there into the cleaning liquid tank 2a by means of the return tube 16.

After being cleaned thematerial by the spray booth 5 is moved to the next treatment tank 1b, where the procedure is repeated.

The treatment in the tanks la-le takes a considerably longer time than the cleaning. In practice there is in the treatment tanks material in different stages of treatment and the spray booth 5 has to serve all this material. After the immersion of the material into a tank, the rack 7 is disconnected from the spray booth 5 and is left in said tank. The spray booth 5 is thereafter moved to another treatment tank to be connected to the rack suspending material there, the treatment of which is finished. This material is then lifted and sprayed by the nozzles 9 and after that moved to the next treatment tank for immersion.

In some cases it can be advantageous to arrange a sort of parking station for material which is waiting for an opportunity to be transported to a following treatment tank. Preferably this station can be made as a cleaning tank 20 which in FIG. 1 is shown to be the last one in the treatment chain and which contains completely clean water. For this purpose the tank is connected to an ion exchange as shown in FIG. 1. The tank 20 can also be used for a last cleaning of the material. It is of course possible to have the tank 20 on another place in the treatment chain, if this for some reason should be advantageous.

The transport mechanism for the material and for the spray booth has here been shown and described to be one and the same. Of course separate driving means can be used for the material and the spray booth.

In FIG. 3 is shown how in the spray booth is inserted two barrels 17. These barrels are provided with a slot 18 through which cleaning liquid by means of a row of nozzles 19 placed horizontally in the spray booth is sprayed to clean the material in the barrel.

Having described our invention, we claim:

1. A cleaning device for chemical or electrochemical surface treatment plants comprising different treatment tanks into which the material to be treated is immersed, driving means for said cleaning device to move it to and above said treatment tanks one at a time, and lifting means to lift the material from said tank, said cleaning device including spray means for a cleaning liquid to spray above said tank said liquid onto the material lifted therefrom.

2. A cleaning device as claimed in claim 1, in which the device includes a spray booth, the bottom of which is provided with an opening through which the material to be treated is taken into the spray booth from beneath.

3. A cleaning device as claimed in claim 2, said spray booth also being provided on its inner walls with nozzles connected to a tank containing the cleaning liquid.

4. A cleaning device as claimed in claim 3, said cleaning liquid tanks being arranged at the side of said treatment tanks.

5. A cleaning device as claimed in claim 3, said nozzles being connected to the respective cleaning liquid tank by means of a flexible tubing, said tubing by moving the spray booth from one treatment tank to another being moved from and to the corresponding cleaning liquid tanks.

6. A cleaning device as claimed in claim 5, said flexible tubing also being connected to a clean-water supply and having valve means to supply said nozzles with either cleaning liquid or clean water.

7. A cleaning device as claimed in claim 2, said spray booth being shaped to collect the quantity of the cleaning liquid which during the spraying does not hit the material, said quantity being returned to said cleaning liquid tank which at that moment is connected to said nozzles.

8. A cleaning device as claimed in claim 2, said spray booth having driving means which are the same as the one required for the transport of the material to preselected treatment tanks. 

1. A cleaning device for chemical or electro-chemical surface treatment plants comprising different treatment tanks into which the material to be treated is immersed, driving means for said cleaning device to move it to and above said treatment tanks one at a time, and lifting means to lift the material from said tank, said cleaning device including spray means for a cleaning liquid to spray above said tank said liquid onto the material lifted therefrom.
 2. A cleaning device as claimed in claim 1, in which the device includes a spray booth, the bottom of which is provided with an opening through which the material to be treated is taken into the spray booth from beneath.
 3. A cleaning device as claimed in claim 2, said spray booth also being provided on its inner walls with nozzles connected to a tank containing the cleaning liquid.
 4. A cleaning device as claimed in claim 3, said cleaning liquid tanks being arranged at the side of said treatment tanks.
 5. A cleaning device as claimed in claim 3, said nozzles being connected to the respective cleaning liquid tank by means of a flexible tubing, said tubing by moving the spray booth from one treatment tank to another being moved from and to the corresponding cleaning liquid tanks.
 6. A cleaning device as claimed in claim 5, said flexible tubing also being connected to a clean-water supply and having valve means to supply said nozzles with either cleaning liquid or clean water.
 7. A cleaning device as claimed in claim 2, said spray booth being shaped to collect the quantity of the cleaning liquid which during the spraying does not hit the material, said quantity being returned to said cleaning liquid tank which at that moment is connected to said nozzles.
 8. A cleaning device as claimed in claim 2, said spray booth having driving means which are the same as the one required for the transport of the material to preselected treatment tanks. 